Symptom
Path MTU Discovery intermittently drops the Tunnel MTU to 972.
To identify this issue, run the debug below.
debug platform hardware qfp active feature bfd datapath pmtu
Once the issue occurs, turn off the debug, run an admin-tech, and open a TAC case to investigate.
Conditions
1. PMTUD is enabled on IOS-XE SD-WAN router.
Workaround
1. Disable PMTUD.
2. Open a TAC case for assistance.
